This invention relates generally to personal identification, and more particularly, to fast matching systems and methods of personal identification using iris information.
There has always been a need for personal identification. With the advances in technology, there is a desire to make the process of personal identification as streamlined as possible by increasing the efficiency and reliability of the methods. Traditional identification methods of requiring identification cards, passwords, codes, etc., are deemed cumbersome and outdated. Thus, there is a desire to take advantage of automated technology to determine a person's identity.
Efforts have been made to utilize biometric information to determine a person's identity. Examples of such efforts include utilizing fingerprints, retinal scans and iris scans. Many of such efforts have focused on verifying, as opposed to identifying, a person's identity. Verifying an identity is a relatively easier situation. With verification, an individual claims a certain identity and then the identification system compares the identification information of the individual with a stored set of identification information for the person they claim to be. This is a one-to-one comparison. Thus, the system merely needs to find the claimed identification information set and compare it to the set of identification information supplied by the individual making the claim.
On the other hand, pure identification is a more difficult problem as the individual does not first make a claim as to their identity, but the system must ascertain it. In this case, the system must compare the identification information supplied by the individual with a large database comprising the identification information of individuals in a large population. This is known as a one-to-many comparison. Thus, the identification of an individual is relatively much more difficult than the verification of an individual's identity.
For example, U.S. Pat. No. 4,641,349 discloses an iris recognition system. The system illuminates an eye, obtains an image of the iris and pupil of the eye, and compares the obtained image with stored image information to identify the eye. Further, the system illuminates the eye to drive the pupil of the eye to a predetermined size, which may then be compared with stored image information from an eye with the same pupil size. The system compares visible features of the iris such as pigment-related features, to stored images of irises to make an identification. The comparison methods identified by this patent include comparing pixel-by-pixel images of two eyes, optical signal processing, and a method in which visual features such as pigment spots are compared between two images. No method is identified, however, for maximizing the efficiency of this comparison.
Similarly, U.S. Pat. No. 5,291,560 discloses a biometric personal identification system based on iris analysis. This system acquires a live video of a person's iris and encodes its texture into a compact signature, or iris code. A coordinate system is utilized to identify portions of the iris, and the iris information from the coordinate system is converted into a 256byte iris code. The iris code has a universal mathematical format and constant length, allowing comparisons between codes using logical operations to determine iris identification. The comparison results in a similarity metric that positively establishes, confirms, or disconfirms the identity of any individual and establishes a confidence level associated with any such identification decision.
None of the prior art, however, identifies techniques for increasing the likelihood of finding a match at the earliest point possible in the comparison process. As such, methods are desired to increase the speed of the identification process.